In the design of information technology and the implementation of radiological diagnostic environments, it is of particular importance to ensure that the image data to be examined are displayed in sufficient quality in order to enable medical evaluation and to avoid faulty diagnoses and incorrect assessments in that, for example, important features of the images cannot be overlooked. To this end, it is, on the one hand, necessary to use selected hardware in order to meet the requirements for the field of medical engineering. On the other hand, it is necessary to adapt the software system to the display requirements.
In particular in clinical environments, but also in systems of doctors in private practice, nowadays it is common for the prior art to use client-server systems in order to prepare and/or transmit or suitably process the image data for diagnostic application or display. To this end, client-server-based applications are implemented on local diagnostic workstations, which for the purposes of control and/or data exchange are dependent to a high degree on the available local network conditions. For flexibility of use, it is frequently desirable to install a diagnostic workstation on a remote viewer, which is controlled by the server-based applications. The data exchange between the application (with the diagnostic software or also with the diagnostic hardware) and the respective viewer (with the display mechanism/monitor) takes place via network connections.
To enable desktop clients to be controlled from remote applications (servers), Microsoft has developed a proprietary network protocol in order to offer terminal services. The Remote Desktop Protocol (RDP) is based on TCP-IP (that is on the transport and internet layer of the ISO/OSI layer model). Here, it is provided that a server (usually called a “terminal server”) generates screen content, which then has to be displayed on the remote terminal client. And vice versa, user interaction input (e.g. in the form of mouse and/or keyboard input) is transmitted from the terminal client via the RDP protocol to the server. Hence, the client can be administered and controlled remotely and hence also centrally, namely from the server. In addition to displaying screen content, it is also possible to transmit acoustic signals to the client. The more recent operating systems from Microsoft, such as, for example, Windows XP, Windows Server 2003 and Windows Vista, support the RDP service and the ICA protocol (ICA: Independent Computing Architecture, Citrix). However, the RDP service can also be used with other operating systems, for example in Linux environments, FreeBSD and with Mac-based operating systems. However, the RDP protocol produces a poor performance since it is not designed for graphics-intensive, highly interactive applications. Alternatives to this known from the prior art are PC-over-IP connections (e.g. Teradici or XenApp (Citrix)).
However, the high-speed LAN-connections known from the prior art (LAN: Local Area Network, such as, for example, RDP protocols) cannot be implemented on a slower WAN connection (WAN: Wide Area Network). This means in the field of image processing medical engineering, separation of the client and is only possible at the expense of quality or even completely impossible, so that the data exchange has to be executed via a slow WAN.
As a rule, the majority of mechanisms for high-speed data transmission are based on keeping the volume of data to be transmitted as low as possible in order to load the network as little as possible. Here, as a rule, lossy compression algorithms are used or the image data to be transmitted are modified in some other way (e.g. by reducing the frame-rate rate). The consequence of this for the field of image-processing medical engineering is that, after transmission, the image data sometimes can no longer be displayed in the required quality on the viewer. These dynamic, network-based manipulations to the data compromise the diagnostic quality of the data so that it cannot be ensured that the diagnostic data are displayed on the remote viewer with the required image quality.
However, this development restricts the use of distributed systems in the field of the medical engineering.
In a medical environment, it is desirable, in particular for diagnostics, to provide a solution with which a client/server system is also able to check and safeguard the quality of the transmitted data for remotely installed viewers for displaying and manipulating medical image data. In addition, an application on the client/server system should be informed of the quality of the data received on the viewer and be able to react specifically and flexibly thereto.